[time-nuts] Modern Rb atomic reference vs classic Cs

[WB6BNQ]

Well,


I fixed two typing mistakes.  Blame it on the corona, too many that is.


Bill WB6BNQ


On 3/13/2020 10:35 PM, WB6BNQ wrote:
>
> *Hello,*
>
> *
> *
>
> *By definition a Cesium frequency standard is just that, an absolute 
> primary reference !  The only difference between the 5061A and another 
> Cesium reference is a matter of degree of closeness to the absolute 
> value.  For example the 5061A has a spec of +/- 1 in 10 to the -11th 
> for accuracy, whereas, 30 years later, the hp5071 has a spec of +/- 1 
> in 10 to the -12th.*
>
> *The Rubidium standard is similar but has a known drift, slight as it 
> is, but does not allow it to be primary standard.  If you have a good 
> working hp-5061A, the best you can say is your standard is good to +/- 
> 1 in ten to the -11th in accuracy.  However, your FS725, while a very 
> nice instrument has to be cross referenced to a primary standard in 
> order to make any kind of absolute statement as to accuracy.*
>
> *
> *
>
> *Bill....WB6BNQ*
>
>
> On 3/13/2020 9:06 PM, Peter Membrey wrote:
>> Hi guys,
>>
>> Potentially a bit of a loaded topic, but I'm really curious as to what the consensus is on this. For the research I've been doing over the past few years, I've been predominantly using an SRS FS-725 (which uses the PRS-10) disciplined by a Microsemi S650 (with the Rb option, though it never went into holdover).
>>
>> Modern Caesium references are expensive compared to the FS-725, but now and then more classic Caesium references become available such as the HP 5061A. These still aren't cheap (actually, not far off a brand new PRS-10) so I was wondering how do they generally compare with a modern Rb?
>>
>> If I have a PRS-10 that's being disciplined by a good GPS source, would I see any benefit if I replaced the PRS-10 with an HP5061A (particularly in terms of stability)?
>>
>> Thanks in advance!
>>
>> Kind Regards,
>>
>>
>> Peter Membrey
>>
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